Cellular communication systems are generally used to provide voice and data communications between one or more communication units within a cellular communication system. The cellular communication units, for example, cellular telephones, mobile radios or other cellular devices, allow communication between one or more users. Cellular data systems are also known that provide packet data communication capabilities that allow communication of voice and data. For example, the General Packet Radio Service (GPRS) standard can be used to communicate voice or other data in packets over a data channel.
In different cellular communication systems, individual users can be able to communicate with a plurality of other users via a group call or other group connection. For example, the Open Mobile Alliance (OMA) standard allows users with mobile devices to communicate using a push-to-talk function, typically referred to as a push-to-talk over cellular (POC) function, with different groups within a cellular communication system. In such systems, users typically establish personal group lists or “buddy” lists on a cellular telephone. Upon depressing a single button, a user is generally able to establish a connection and communicate with or broadcast a message to multiple users.
The communications between devices corresponding to the personal group lists or “buddy” lists typically include small numbers of users or subscribers. However, if the particular cellular communication coverage area or communication cell in which a group communication is occurring becomes overloaded such that the capacity is exceeded (e.g., bandwidth exceeded), some of the participants in the group call can be unable to connect to the communication link (or some are dropped). Therefore, those members of the group will not be able to participate in the communications and will not be able to listen to the message or obtain the data transmitted over the group connection. However, because this type of personal communication is often not time critical, there are generally minimal or no serious consequences resulting from such loss of connection or inability to connect by some users or subscribers. However, in other types of communication, such as emergency group calls, loss of connection or inability to connect to a call can have serious (sometimes life threatening) consequences.
In general, user equipment and other equipment external to the cellular core network also is typically unable to detect the amount of activity in a particular cell or determine an amount of usage relative to a maximum number of users, a maximum capacity, or otherwise. Accordingly, the cellular communication system or network will typically not provide any type of notification or alert when the system is reaching or about to reach a maximum level or capacity. Consequently, additional units attempting to establish a communication link using an overloaded cell, such as to join a group call, can not be able to join and additionally there will be no prior indication that such denial of access is about to occur. Moreover, there is generally no means to prevent such a denial of service from occurring. Thus, because there is no indication from the network of when a particular cell is reaching a maximum level or capacity, there typically is no way to control or otherwise reduce the likelihood that individuals or units attempting to connect with a particular uplink or downlink will not be able to access that uplink or downlink connection to join a group call.